package com.yale.test.ps;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import javax.crypto.KeyGenerator;

import javax.crypto.Mac;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

/*

* Hmac算法

* HMAC(Hash Message Authentication Code，散列消息鉴别码)，基于密钥的Hash算法的认证协议。消息鉴别码实现鉴别的原理是，用公开函数和密钥产生一个固定长度的值作为认证标识，

* 用这个标识鉴别消息的完整性。使用一个密钥生成一个固定大小的小数据块，即MAC，并将其加入到消息中，然后传输。接收方利用与发送方共享的密钥进行鉴别认证等。

* http://www.jfh.com/jfperiodical/article/818

*/

public class Hmac2 {

public static final String KEY_MAC = "HmacMD5";

public static void main(String[] args) {

try {

String str = "简单加密";

//使用同一密钥:对数据进行加密:查看俩次加密的结果是否一样

getResult1(str);

getResult2(str);

} catch (NoSuchAlgorithmException e) {

e.printStackTrace();

} catch (InvalidKeyException e) {

e.printStackTrace();

} catch (IllegalStateException e) {

e.printStackTrace();

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

}

/*

* 初始化HMAC密钥

*/

public static String initMacKey() throws NoSuchAlgorithmException {

KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);

SecretKey secretKey = keyGenerator.generateKey();

return Base64Test.encryptBASE64(secretKey.getEncoded());

}

/*

* HMAC加密:主要方法

*/

public static String encryptHMAC(byte[] data, String key) throws IOException, NoSuchAlgorithmException, InvalidKeyException {

SecretKey secretKey = new SecretKeySpec(Base64Test.decryptBASE64(key), KEY_MAC);

Mac mac = Mac.getInstance(secretKey.getAlgorithm());

mac.init(secretKey);

return new String(mac.doFinal(data));

}

public static String getResult1(String inputStr) throws NoSuchAlgorithmException, InvalidKeyException, IOException {

String path = "";//Tools.getClassPath()

String fileSource = path + "/file/HMAC_key.txt";

System.out.println("==================加密前的数据:" + inputStr);

byte[] inputdata = inputStr.getBytes();

String key = Hmac2.initMacKey();//产生密钥

System.out.println("Mac密钥:===" + key);

//将密钥写入文件Tools.WriteMyFile(fileSource, key);

String result = Hmac2.encryptHMAC(inputdata, key);//加密

System.out.println("HMAC加密后:======" + result);

return result;

}

public static String getResult2(String inputStr) throws InvalidKeyException, NoSuchAlgorithmException, IOException {

System.out.println("加密前的数据==========" + inputStr);

String path = "";//Tools.getClassPath();

String fileSource = path + "/file/HMAC_key.txt";

String key = null;

//将密钥从文件中读取

key = ""; //Tools.ReadMyFile(fileSource)

System.out.println("读取的密钥为:=================" + key);

byte[] inputData = inputStr.getBytes();

//对数据进行加密

String result = Hmac2.encryptHMAC(inputData, key);

System.out.println("HMAC加密后:===" + result);

return result;

}

}